docs: def get_seqprop_within(self, chain_id, resnum, angstroms, only_protein=True,
                             use_ca=False, custom_coord=None, return_resnums=False):
          """Get a SeqProp object of the amino acids within X angstroms of the specified chain + residue number.
  
          Args:
              resnum (int): Residue number of the structure
              chain_id (str): Chain ID of the residue number
              angstroms (float): Radius of the search sphere
              only_protein (bool): If only protein atoms (no HETATMS) should be included in the returned sequence
              use_ca (bool): If the alpha-carbon atom should be used for searching, default is False (last atom of residue used)
  
          Returns:
              SeqProp: Sequence that represents the amino acids in the vicinity of your residue number.
  
          """
          # XTODO: change "remove" parameter to be clean_seq and to remove all non standard amino acids
          # TODO: make return_resnums smarter
          polypep, resnums = self.get_polypeptide_within(chain_id=chain_id, resnum=resnum, angstroms=angstroms, use_ca=use_ca,
                                                        only_protein=only_protein, custom_coord=custom_coord,
                                                        return_resnums=True)
  
          # final_seq = polypep.get_sequence()
          # seqprop = SeqProp(id='{}-{}_within_{}_of_{}'.format(self.id, chain_id, angstroms, resnum),
          #                   seq=final_seq)
  
          chain_subseq = self.chains.get_by_id(chain_id).get_subsequence(resnums)
  
          if return_resnums:
              return chain_subseq, resnums
          else:
              return chain_subseq